Booking Form Date Error Fix

My booking form suddenly rejects every attempt to pick a date and flashes the message “Selected date is not valid.” Even when the date is clearly within the allowed range, the form refuses to proceed and blocks submission. I’m looking for someone to trace the root cause of this error message, correct the validation logic, and confirm the form submits smoothly once a valid date is chosen.

You’ll work with the existing front-end (HTML/CSS/JavaScript) and back-end script that processes the reservation. No styling changes are needed—just the functional repair. Please test across the latest versions of Chrome, Firefox, Safari, and Edge so guests on any browser can complete a booking without errors.

Deliverables:
• Updated code (front and/or back end) that eliminates the “Selected date is not valid” error
• Confirmation that the form now submits successfully with legitimate dates
• A brief note summarising what you changed so I can maintain it going forward

If you need server access or sample inputs, let me know and I’ll provide them right away.